Ulnar Head Research Articles

The Transverse Sigmoid Notch Morphology Unravelled.

Background: Several studies have described pathology in relation to transverse sigmoid notch morphology, using the Tolat transverse sigmoid notch classification. It is believed that the entire shape of a sigmoid notch can be described using Tolat sigmoid types. We hypothesised that the determination of the sigmoid notch shape (SNS) depends on the level of the transverse CT plane on the axial axis of the distal radius. The aim of this study was to determine and compare the transverse SNS on different axial CT levels in the same wrist. Methods: The transverse SNS of 53 participants were independently qualitatively classified by two researchers in accordance with the four morphologies described by Tolat et al. The SNS was determined at two levels on the axial axis of the distal radius; at the level of the most prominent part of Lister tubercle, determined on the sagittal plane and at the level of the 'smallest distance between the ulnar head and sigmoid notch' (SDUS). Results: Forty-seven percent of the wrists demonstrated different SNS types according to Tolat classification, depending on the axial level of the CT scan. Interobserver agreement on the transverse sigmoid shape was 87% at Lister tubercle and 85% at SDUS, which can both be interpreted as 'excellent'. Conclusions: Despite an excellent interobserver agreement, 47% of the study population had different transverse sigmoid notch types within the same wrist. We, therefore, conclude that Tolat transverse sigmoid classification may not be useful for the description of potential pathology in relation to the sigmoid notch morphology.

Thermal measurement of erythema across skin tones: Implications for clinical identification of early pressure injury

AimTo assess the effectiveness of thermography, colorimetry, and oximetry at detecting temperature changes after erythema induction across diverse skin tones in healthy adults. Materials and methodsErythema was induced at the forearm and ulnar head (UH) using a cupping device. Temperature via thermal image, erythema value via colorimeter, and oxygen saturation via oximeter were collected immediately and 5–10 min (delayed) after cupping at both sites. ResultsAt the forearm, the delayed timepoint was significantly warmer than baseline. At the UH, the immediate timepoint was significantly colder than baseline. Erythema increased at both timepoints and both locations. The correlation between temperature change and erythema change was weak. Change in temperature did not differ between skin tone groups. The Intermediate Low Eumelanin skin tone group had more change in erythema compared to the Intermediate Mid (i.e., darkest) skin tone group immediately after cupping at the UH and at the delayed timepoint at the forearm. ConclusionsThis study observed differences in the change of erythema across skin tones but did not observe differences in temperature across skin tones. Given high variability in results, it is premature to conclude thermal imaging works equally well across all skin tones. Further research is necessary to validate the effectiveness of thermal imaging in diverse populations. Results suggest visual erythema may be a problematic indicator as less erythema was consistently noted in participants with dark skin tones. The potential of technology to increase our ability to detect erythema warrants further investigation.

Bilateral Variations of Pronator Teres in the Upper Limb.

During clinical practice, physicians need to have a sound knowledge of vascular and nerve variations in the body. Patients presenting with various clinical signs and symptoms need to be thoroughly investigated with anatomic variations in mind to prevent misdiagnosis. Most nerve variations are related to their formation or their course and are frequently associated with the variability of structures that surround them. These structures most commonly include blood vessels, ligaments, and muscles. Such variations should be foremost in a physician's mind when analyzing clinical symptoms. This will aid in accurate diagnosis, and if surgical intervention is warranted, such awareness would minimize intraoperative errors. This article discusses a variation in the pronator teres muscle, the branching pattern of the brachial artery, and the median nerve. During the dissection of 11 cadaveric specimens within the Geisinger Commonwealth School of Medicine, an elderly female cadaver exhibited bilateral variations in the pronator teres muscle, which originated from the mid-humerus, instead of the medial epicondyle. Careful dissection revealed associated neurovascular variations in the arm, elbow, and forearm in relation to the muscle. The pronator teres muscles in the remaining 10 cadavers in the lab were examined for variations and their lengths were measured and compared with the cadaver under study. Unlike the normal origin at the medial epicondyle as described in textbooks, it was observed that the humeral heads of the pronator teres muscle originated at mid-humerus level bilaterally,associated with the passage of the median nerve and ulnar artery posterior to it. This muscle was 19 cm in length bilaterally, approximately 5.5 cm longer than the average lengths of pronator teres measured bilaterally in the other cadavers. The abnormally high origin of this muscle was associated with the finding of a median nerve coursing posterior to it to the forearm, failing to appear in the antecubital fossa. Although the ulnar head appeared normal, there were bilateral variations in the median nerve during its passage between the two heads of the pronator teres at the proximal forearmas it proceeded to the deeper compartment of the forearm. The brachial artery was observed to divide into radial and ulnar arteries at the mid-humerus level. The radial artery replaced the brachial artery in the antecubital fossa and the ulnar artery accompanied the median nerve posterior to pronator teres into the forearm. Such variations observed bilaterally have not yet been reported in the literature. Knowledge of these variations in the origin of pronator teres muscle, the absence of specific neurovascular structures as expected within the cubital fossa, and the awareness of early bifurcation and variation in their course can be very profound for physicians, as this region is often involved in the creation of arterio-venous fistulas for medical procedures, surgical treatment options for supracondylar and radial head fractures, and to differentiate median nerve compression in pronator teres syndrome versus carpal tunnel syndrome.

A modified partial wedge-shaped metaphyseal ulnar osteotomy for the treatment of ulnar impaction syndrome with reverse oblique sigmoid notch.

We describe a modified metaphyseal ulnar osteotomy to treat ulnar impaction syndrome with a reverse oblique sigmoid notch. Based on a computational analysis of radiographs, a modified wedge metaphyseal ulnar osteotomy was devised with its apex positioned at the ulnar styloid base to avoid impaction between the sigmoid notch and ulnar head. Subsequently, nine patients with ulnar impaction syndrome and a reverse oblique sigmoid notch underwent this operation, combined with arthroscopic exploration and transosseous triangular fibrocartilage complex repair. The mean follow-up was 14 months. All patients achieved bone union within 5 weeks, with no degenerative changes being observed during the follow-up assessments. The final follow-up assessments revealed decreases in ulnar variance and in the scores for Visual Analogue Scale, Quick Disabilities of the Arm, Shoulder and Hand questionnaire and the Patient-Rated Wrist Evaluation. All patients achieved excellent or good grades on the Modified Mayo Wrist Score. This technique is effective in treating the ulnar impaction syndrome with a reverse oblique sigmoid notch.Level of evidence: IV.

Distinct patterns of fracture propagation in distal radial fractures and the relationship to the ulnar head

BackgroundThe aim was to assess the direction of distal radius fractures and their relationship to the ulnar head. MethodsWe reviewed the 160 wrist radiographs. The fracture line was measured on the postero-anterior and lateral radiographs relative to the long axis of the forearm and the relationship to the ulnar head. FindingsPA radiographs: the fracture line ran distal ulnar to proximal radial (ulnar to radial) in 11%, transverse in 74% and distal radial to proximal ulnar (radial to ulnar) in 16%. Lateral radiographs: the fracture line ran distal volar to proximal dorsal in 88%, transverse in two 1% and dorsal to volar in 11%. Radial shift (7.5%) only occurred with ulnar to radial or transverse fractures.The ulnar to radial fracture line started at the proximal end of the ulnar head/distal radio-ulnar joint in 88%. The radial to ulnar fracture line started ended a mean of 2.5 mm proximal to the distal radio-ulnar joint (p < 0.01). The transverse fracture line started at the base of the distal radio-ulnar joint in 53% and proximally in 47%. InterpretationThere are two distinct coronal patterns: radial to ulnar ending c. 2 mm proximal to the distal radio-ulnar joint; ulnar to radial starting at the proximal distal radio-ulnar joint. There may be third pattern - transverse fractures; these may be variants of the above. Sagittally the main direction is volar to dorsal but 11% are obverse.This is the first description of distinct fracture patterns in extra-articular distal radius fractures. In addition the fracture patterns appear to correlate with different directions of force transmission which fit with our understanding of falling and the relatively uncontrolled impact of the wrist/hand with the ground.These patterns of fracture propagation help understand how the biomechanics of wrist fractures and may enable prediction of collapse.

Clinical and radiological aspects of the forearm in children with congenital radioulnar synostosis: a cohort study

Introduction The upper limb functional limitations in congenital radioulnar synostosis may significantly affect the daily activities of patients. Classifications of the condition are descriptive and have limited practical application.Purpose Determine a functionally significant quantitative criterion for anatomical changes in the forearm.Material and methods 92 children (136 forearms) with congenital radioulnar synostosis were examined for limitations in activities of daily living (ADL), health-related quality of life measured with PedsQL questionnaire; pronation of the forearm and radiographic parameters. A comparative and correlation analysis, ROC analysis were performed to determine the relationship between the forearm pronation and limitations of ADL.Results Statistically significant correlations were revealed between symptoms and the forearm alignment (p &lt; 0.01, rxy = 0.5); subluxation of the ulnar head and forearm alignment (p &lt; 0.001, rxy = 0.6); bowing deformity of the radius, forearm alignment and subluxation of the ulnar head and between the length of the forearm bones and bowing deformity of the radius (p &lt; 0.05, rxy = 0.4 and rxy = 0.5). A statistically significant inverse correlation was revealed between symptoms and PedsQL scores (p = 0.038, rxy = –0.4). Pronation of 45° was the threshold value of the forearm alignment with a high risk of ADL limitation. The area under the ROC curve corresponding to the relationship between symptoms and the forearm alignment was 0.955 ± 0.021 (95 % CI: 0.915–0.995). There was a statistically significant (p &lt; 0.01) decrease in the lumen of the medullary canal in the middle third of the ulnar shaft with the radius lumen being unchanged. Dorsal subluxation of the ulnar head was detected In 30 % of cases.Discussion The characteristics identified demonstrated changes in the forearm bones with functional impairments being correlated with the forearm pronation.Conclusion The correlation between the patient’s symptoms and the forearm alignment must be taken into account in the classification and when determining indications for surgical treatment distinguishing between functional (&lt; 45° pronation) and dysfunctional (≥ 45° pronation) options.

Long-term survivorship of the Herbert ulnar head prosthesis: a multicentre retrospective cohort study.

IV.

Analyzing the reduction quality of the distal radioulnar joint after closed K-wire transfixation in a cadaver model: is supination or neutral position superior?

Distal radioulnar joint (DRUJ) instabilities are challenging and their optimal treatment is controversial. In special cases or when reconstruction of the stabilizing triangular fibrocartilage complex (TFCC) fails, K-wire transfixation can be performed. However, no consensus has been reached regarding the rotational position of the forearm in which this should be done. Therefore, it was investigated whether anatomical reduction would best be achieved by transfixation in neutral position or supination of the forearm. Twelve cadaveric upper limbs were examined before dissection of the DRUJ stabilizing ligaments and after closed transfixation in both positions by C-arm cone-beam CT. Whether this was first done in neutral position or in supination was randomized. The change in the radioulnar ratio (RR) in percentage points (%points) was analyzed using Student's t-test. RR was used since it is a common and sensitive method to evaluate DRUJ reduction, expressing the ulnar head's position in the sigmoid notch as a length ratio. The analysis showed an increased change in RR in neutral position with 5.4 ± 9.7%points compared to fixation in supination with 0.2 ± 16.1%points, yet this was not statistically significant (p = 0.404). Neither position leads to a superior reduction in general. However, the result was slightly closer to the anatomical position in supination. Thus, transfixation of the DRUJ should be performed in the position in which reduction could best be achieved and based on these data, that tends to be in supination. Further studies are necessary to validate these findings and to identify influential factors.

Reverse Wafer Procedure for Ulnar Impaction Syndrome.

Ulnar impaction syndrome occurs when excessive load across the ulnocarpal joints results in pathologic changes, especially over the articular surface of the ulnar head and proximal ulnar corner of the lunate. The 2 main surgical options in ulnar impaction syndrome are ulnar shortening osteotomy and wafer procedure, whether open or arthroscopically, to decompress the ulnocarpal joint load. However, all of these techniques have their shortcomings and drawbacks. The current study demonstrates a novel technique to decompress the ulnocarpal joint load: the "reverse wafer procedure" for ulnar impaction syndrome. In this surgical technique, we resected the proximal ulnar side of the lunate instead of partial resection of the thin wafer of the distal ulnar head dome in the standard wafer procedure. This technique avoids iatrogenic central tear of triangular fibrocartilage and distal radioulnar joint portal arthroscopy, which is technically demanding while preserving the distal radioulnar joint.

Optimal Limb Position for the Stress Ultrasound Evaluation of Elbow Valgus Laxity in Baseball Players.

The optimal limb position during stress ultrasound (SUS) evaluation of elbow valgus laxity has not been standardized. To compare 2 elbow positions (at 90° and 30° of flexion) and report which position method better represents the increased valgus laxity characteristics of baseball players. Controlled laboratory study. Eighteen college baseball players with no history of elbow pain or elbow disorders who belonged to a college baseball club between April and November 2021 participated in this study. The medial elbow joint space (MEJS) was recorded by ultrasonography at rest and under valgus stress, and the difference in MEJS between the conditions was considered the valgus laxity. For all participants, the MEJS was recorded at 90° and 30° of elbow flexion. In the 90° of flexion position, the participant was positioned in the supine position with abduction and external rotation of the shoulder, and 2.5 kgf of valgus stress was applied proximally to the wrist. In the 30° of flexion position, the participant was positioned in the sitting position with abduction and external rotation of the shoulder, and 3.0 kgf of valgus stress was applied to the ulnar head. Valgus laxity on the throwing and nonthrowing sides was compared between the 2 elbow positions using paired t tests or Wilcoxon signed-rank tests after checking the normality. There was a significant difference in valgus laxity on the throwing side between the 90° and 30° of flexion positions (1.9 vs 1.1 mm, respectively; P = .002), whereas no significant difference between positions was seen on the nonthrowing side (P = .06). SUS with the elbow flexed at 90° more clearly detected valgus laxity in the study participants than the 30° of flexion position. The quantitative evaluation of valgus laxity is important for baseball players to assess the risk of ulnar collateral ligament injury.

Comparing the Outcomes of Suture Anchor Repair and Rein-Type Capsular Suture for Triangular Fibrocartilage Complex Foveal Tears With a Minimum 2-Year Follow-Up

Recent biomechanical studies have highlighted the importance of foveal reinsertion when repairing triangular fibrocartilage complex (TFCC) injury with foveal tears. However, clinical studies comparing different repair techniques are scarce. We compared the clinical outcomes of suture anchor repair and rein-type capsular suture in patients with TFCC palmer 1B foveal tears with a minimum of 2-year follow-up. This was a single-surgeon, single-center, retrospective, comparative study. We included patients who underwent TFCC repair surgery due to a foveal tear from December 2013 to October 2018 with a minimum follow-up of 24 months. Postoperative Quick Disabilities of Arm, Shoulder, and Hand (QuickDASH) score, Modified Mayo Wrist Score, visual analogue scale for pain, wrist range of motion, and grip strength were compared. We also measured the maximal ulnar head displacement with dynamic ultrasound to quantify distal radioulnar joint stability. In total, 103 patients were in the suture anchor group (group A) and 84 patients in the rein-type capsular suture group (group B). The mean follow-up time exceeded three years for both groups. There was a minimal difference regarding QuickDASH score, visual analogue scale for pain, and grip strength ratio between the two groups. The rein-type group had significantly better Modified Mayo Wrist Score. The suture anchor group showed better distal radioulnar joint stability with dynamic ultrasound, but was more limited in ulnar deviation. However, these differences are most likely clinically insignificant. Both suture anchor repair and rein-type capsular suture yielded satisfactory results for TFCC 1B foveal tear in a minimum of 2-year follow-up. The functional scores were similar, and no major complications or recurrent instability were noted in either group. Retrospective therapeutic comparative investigation IV.

Extensor Carpi Ulnaris “Turn Around” Ligamentoplasty For Distal Radioulnar Joint Instability

Extensor Carpi Ulnaris “Turn Around” Ligamentoplasty For Distal Radioulnar Joint Instability

Ulnar Head Fracture with Volar Dislocation of the Distal Radioulnar Joint: A Case Series and Systematic Review

AbstractDislocations of the distal radioulnar joint associated with a fracture of the distal ulna articular surface without an associated radial fracture are extremely rare.We present a case of a fracture of the distal ulna with an associated dislocation of the distal radioulnar joint, where the articular head fragment was displaced anterior to the sigmoid notch.We also present the results of a formal systematic review of these injuries which confirmed this is the first such injury described, although there is a very similar fracture pattern described in the literature with dorsal dislocation.We describe the mechanism of injury and hypothesize about the etiology of the fracture pattern and suggest that it represents the end of a spectrum that also includes the isolated dislocations and those associated with an ulna styloid fracture.

Surgical fixation of distal ulna neck and head fractures.

Distal ulna plate fixation for ulnar neck and head fractures (excluding ulnar styloid fractures) aims to anatomically reduce the distal ulna fracture (DUF) by open reduction and internal fixation, while obtaining astable construct allowing functional rehabilitation without need for cast immobilization. Severe displacement, angulation or translation, as well as unstable or intra-articular fractures. Furthermore, multiple trauma or young patients in need of quick functional rehabilitation. Inability to surgically address concomitant ipsilateral extremity fractures, thus, limiting early active rehabilitation. Stable, nondisplaced fractures. Need for bridging plate or external fixator of distal radiocarpal joint. An ulnar approach, with astraight incision between the extensor and flexor carpi ulnaris. Preservation of the dorsal branch of the ulnar nerve. Reduction and plate fixation with avoidance of plate impingement in the articular zone. Postoperatively, an elastic bandage is applied for the first 24-48 h. In isolated DUF with stable fixation, apostoperative splint is often unnecessary and should be avoided. For the first fourweeks, only light weightbearing of everyday activities is allowed to protect the osteosynthesis. Thereafter, heavier weightbearing and activities are allowed and can be increased as tolerated. The best available evidence likely shows that for younger patients with aDUF, with or without concomitant distal radius fractures, open reduction and internal fixation can be safely achieved with good functional outcome and acceptable union and complication rates as long as proper technique is ensured.

Using Technology to Detect Erythema Across Skin Tones.

To examine the effectiveness of the ColorMeter DSM III (ColorMeter; Cortex Technology) at grouping individuals by skin tone and measuring erythema/skin discoloration after erythema induction across skin tones. This pre/post experimental study induced erythema on a convenience sample of 61 healthy adults. Skin tone at baseline was measured using the ColorMeter, Munsell Soil Color Chart 5YR (Munsell), and Pantone SkinTone Guide (Pantone) and compared with the Eumelanin Human Skin Colour Scale (Eumelanin Scale) groupings. Erythema and melanin values on the arm immediately and after recovery time were compared with baseline values. Melanin was measured at five body regions on the face and arm. Participants were predominantly women (64% [n = 39] women, 36% [n = 22] men) and young (mean, 28.8 ± 14.3 years); 5% (n = 3) were Hispanic, 26% (n = 16) Asian, 29% (n = 18) Black, 38% (n = 23) White, and 7% (n = 4) identified with more than one race. ColorMeter lightness (L*) and melanin measures were strongly correlated with both Munsell and Pantone values. Munsell skin tone groups were not aligned with Eumelanin Scale groupings. Most participants were in the Eumelanin intermediate-low group, and this changed depending on which body location melanin value was used. The change in erythema from baseline did not differ significantly across skin tone groups at the ulnar head, but on the forearm at the delayed time point, significant differences existed between light and both medium and dark skin tone groups (P = .001; 95% CI, 0.04-0.37). The ColorMeter provides an effective objective measure of skin tone and erythema/discoloration across various skin tones and may improve on current standards for detection. The proposed Eumelanin Scale-Modified provides additional sensitivity for persons with medium skin tones.

Giant cell tumors of the distal ulna: long-term recurrence rate and functional outcomes of en bloc resection versus curettage in a multicenter study

ObjectiveThe wrist is the second most commonly involved location for GCTB, while distal ulna is a relatively rare location and limited evidence exists on which surgical approaches and reconstruction techniques are optimal. We carried out a multicenter retrospective study to evaluate the recurrence rate of distal ulna GCTB and the long-term functional outcomes of different surgery options.MethodsAll 28 patients received surgical treatment for distal ulna GCTB in one of three tertiary bone tumor centers between May 2007 and January 2021 with a minimum two-year follow-up. Surgical options included intralesional curettage or en bloc resection (one of 3 types). Functional outcomes were assessed by the MSTS score, the QuickDASH instrument, MWS, and MHQ according to the latest treatment.ResultsOverall recurrence rate was 14.2%. The curettage group (N = 7) had a significantly higher recurrence rate compared to en bloc resection (N = 21) (42.9% vs 4.8%) (mean follow-up: 88.8 mo). Seven patients received the Darrach procedure, 5 received the original Sauvé–Kapandji procedure, and 9 received the modified Sauvé–Kapandji procedure with extensor carpi ulnaris (ECU) tenodesis. Of the 4 patients having a recurrence, 1 received the Darrach EBR, 2 received the modified Sauvé–Kapandji procedure, and 1 received resection for soft tissue recurrence. Only MWS and esthetics in the MHQ scores were different (curettage, Darrach, Sauvé–Kapandji, and Sauvé–Kapandji with ECU tenodesis [MWS: 96.5 ± 1.3 vs 91.5 ± 4.7 vs 90.8 ± 2.8 vs 91.5 ± 3.6; esthetics in MHQ: 98.5 ± 3.1 vs 89.9 ± 4.7 vs 93.8 ± 4.4 vs 92.6 ± 3.8], respectively).ConclusionsEn bloc resection for distal ulna GCTB had a significantly lower recurrence rate compared with curettage and achieved favorable functional outcome scores. Given the higher recurrence rate after curettage, patients should be well informed of the potential benefits and risks of selecting the distal radioulnar joint-preserving procedure. Moreover, reconstructions after tumor resection of the ulna head do not appear to be necessary.

Antegrade Fixation of Distal Metaphyseal Ulnar Shortening Osteotomy.

The ulnar shortening osteotomy (USO) is a common procedure used to treat ulnar impaction syndrome secondary to static or dynamic ulnar-positive variance. There are many described techniques for the USO. The distal metaphyseal ulnar shortening osteotomy (DMUSO) with retrograde cannulated screw fixation was described to reduce complications seen with other techniques. Biomechanical analysis of fixation constructs demonstrates 2-screw constructs are significantly stiffer than 1 screw and antegrade constructs have similar or greater stiffness when compared with retrograde constructs. Here, we describe a technique of antegrade cannulated screw fixation for DMUSO that obviates the need for the disruption of the distal radioulnar joint for intra-articular exposure of the ulnar head. Similar to the traditional retrograde DMUSO technique, this construct may also decrease the risk of delayed union, symptomatic implants associated with diaphyseal osteotomies, and disruption of triangular fibrocartilaginous complex in wafer procedures.

Hemiresection Capsuloretinacular Interposition Arthroplasty for Distal Radioulnar Joint Osteoarthritis

Abstract Background Hemiresection interposition arthroplasty (HIA), which can preserve triangular fibrocartilage complex (TFCC) and distal radioulnar joint (DRUJ) function, is one of the surgical options for DRUJ osteoarthritis. Description of Technique An arcuate vertical incision of approximately 8 cm was made, and the flap, including both the extensor retinaculum and dorsal DRUJ capsule, was wrapped around the resected ulnar head. In cases where the TFCC was torn, repair or reconstruction was also performed. Patients and Methods Twenty-one wrists in 20 patients with DRUJ osteoarthritis were treated. Patients with rheumatoid arthritis were excluded. Preoperative ulnar variance value averaged 1.8 mm. The average length of follow-up period was 2 years and 10 months. Functional outcomes were evaluated by visual analog scale (VAS) for wrist pain, Disabilities of the Arm, Shoulder, and Hand, Patient-Rated Wrist Evaluation (PRWE), range of wrist and forearm motion (palmar-dorsal flexion and pronation-supination), and grip strength (% of the contralateral value). X-ray parameters (width of the ulnar head, DRUJ distance) were assessed. Results The postoperative grip strength and range of wrist and forearm motion improved significantly, and VAS for pain and PRWE improved larger than minimum clinical important difference. The DRUJ gap distance was maintained sufficiently in average value of 5.3 mm at the final follow-up. Conclusion The current modified HIA procedure combined with TFCC repair or reconstruction provides feasible short-term functional outcomes for treatment of patients with DRUJ osteoarthritis regardless of preoperative ulnar variance.

Replacement of the distal radio-ulnar joint with asemi-constrained Scheker DRUJ prosthesis.

To describe the indications, operative technique, and long-term outcomes of patients treated with the Scheker (Aptis) distal radio-ulnar joint (DRUJ) prosthesis. The Scheker prosthesis is intended to replace the DRUJ in patients with rheumatoid, degenerative, or posttraumatic arthritis of the sigmoid notch and/or ulnar head, or in cases of gross instability of the DRUJ. Moreover, aScheker prosthesis can be used to treat failed salvage procedures, such as the Sauvé-Kapandji procedure, ulnar head resection, and ulnar head arthroplasty. Severe osteoporosis, active infection, immature skeleton, less than 14cm of the proximal ulna remaining. In supine position with the forearm in full pronation, an ulnar S‑shaped incision is made. The ulnar head is resected and the proximal part is brought to the palmar side to enable visualization of the sigmoid notch. Following preparation of the sigmoid notch and the proximal ulnar part of the radius, aradial plate is attached. When the position is verified with fluoroscopy, screw holes are drilled together with aseparate hole for the radial peg. Ametal stem is inserted in the ulnar shaft. Apolymer ball is then slid on to apolished peg on top of the ulnar stem. This polymer ball is seated in the socket of the radial plate and fixed with asmall metal cap. Radiographic images are made for confirmation of correct positioning and full pro- and supination is tested, after which the wound is closed. After 48 h of pressure bandages, patients are instructed to start with full range of motion and weight-bearing exercises under the guidance of ahand therapist. Weight-bearing is constrained to 10kg. We retrospectively assessed 50Scheker prostheses in 48patients treated between 2016 and 2021. The median age was 56years (IQR: 50-65) and 30 (60%) were female. Median follow-up was 29months (IQR: 12-48). The primary outcome was the PRWE score. The median PRWE score at the final follow-up was 23 (IQR: 4-52) for the operated side versus amedian PRWE score of 5 (IQR: 0-25) for the non-operated side (p < 0.005). Six patients had acomplication. Three patients developed extensor carpi ulnaris tendinitis with one patient requiring additional surgery. One patient developed aneuroma of the distal branch of the ulnar nerve that was surgically removed. One synovectomy was performed because of synovitis and one endoscopic ulnar release was performed because of hyperesthesia of the ulnar area. None of the prostheses had to be removed.

The Hook Test Is Not Pathognomonic for Foveal Detachment of the Triangular Fibrocartilage.

Background The integrity of the foveal insertion of the triangular fibrocartilage complex (TFCC) is currently assessed by inference using the hook test. Using dry arthroscopic techniques, the primary author observed that many patients with painful distal radioulnar joint (DRUJ) instability and a positive hook test had an intact foveal insertion. This study was performed to determine whether a positive hook test is a reliable index of a tear of the foveal insertion. Technique The hook test is performed using a probe to elevate the TFCC off the ulna head toward the articular surface of the lunate. In this study, the hook test was considered positive if the TFCC could be elevated to bridge more than 80% of the space between the TFCC and the articular surface of the lunate. Patients and Methods A retrospective study was performed using the medical records and arthroscopic videos of 113 patients who had clinical signs of DRUJ instability and underwent arthroscopic surgery performed by the primary author in 2020. It was documented whether the hook test was positive or negative, whether the foveal insertion was intact, abnormal or absent, and whether there were peripheral (dorsal or volar) tears of the TFCC. Sensitivity and specificity were calculated using arthroscopic findings as the reference standard. Results The sensitivity of the hook test was found to be 100%, and the specificity was 7.0%. The positive predictive value for foveal pathology was found to be 12.3% and the negative predictive value 100%. The diagnostic accuracy of the hook test in determining the presence of foveal tears was found to be 17.7%. The diagnostic accuracy of the hook test in determining the presence of a TFCC abnormality was 99.1%. Conclusions A positive hook test is indicative of a tear of the TFCC, but it is not anatomically specific for a tear of the foveal insertion. To reliably assess the foveal insertion, it must be visualized and probed using dry arthroscopic techniques.